The present invention relates to a disk array apparatus and a method for controlling the disk array apparatus. More particularly, this invention relates to an improvement of a function to restore a disk drive from a failure.
Recently, in line with the advances in IT technology, attempts have been made to achieve high performance, high capacity, and low cost in a disk array apparatus as a storage controller. The disk array apparatus includes a large number of disk drives allocated in an array. The logical configuration of the disk drives allocated in an array is based on RAID (Redundant Arrays of Independent [or Inexpensive] Disks). A host computer issues a write-access command or a read-access command to the disk array apparatus and is thereby capable of reading or writing data from or to a disk drive.
Japanese Patent Laid-Open (Kokai) Publication No. 2004-348876 discloses an example of the above-described type of disk array apparatus. As shown in FIG. 5 of this publication, the disk array apparatus includes a controller 100. The controller 100 has: a communication control unit 110 for accepting data input/output requests; a disk controller 120 for controlling disk drives 51α and 51β; and a cache memory 62 for temporarily storing data sent and received between the communication control unit and the disk controller. The controller 110 sends and receives data to and from the disk drive 51β, which has a different interface, via the disk controller 120 and a converter 170.
Moreover, Japanese Laid-Open (Kokai) Publication No. 2002-23967 discloses a drive failure recovery method comprising the steps of: physically moving a storage medium relative to a drive device; performing processing to reboot the drive device; performing processing to hard reset the drive device; and turning off or repowering the drive device; wherein the processing proceeds in the order of the above-listed steps and terminates when the drive device recovers from a failure in any of the steps.